<!--
 * @Author: your name
 * @Date: 2021-08-23 10:02:39
 * @LastEditTime: 2021-08-23 15:17:41
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \briup\5-javascript\2-2-JavaScript\day01\world.html
-->
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="">
    <script type="text/javascript">
        //type可写可不写
        //js语言，内部引入
        var a = 10;
        console.log(a);
    </script>
</head>

<body>
    <button>按钮</button>
    <script>
        var b = document.getElementsByTagName("button")[0]; //DOM
        console.log(b);
        alert("111"); //BOM
        var a = "hell0";
        console.log(a.charAt(3));
    </script>

    <script src="world.js"></script> //外部引入
    <script src="briup.js"></script>

</body>

</html>